Oil cooler

ABSTRACT

In an oil cooler, oil flow inlet and oil flow outlet are respectively opened on the laminated core itself at overlapped parts of a laminated core, the laminated core constituting a heat exchanger, and a base plate, with respect to at least one of the oil flow inlet and the oil flow outlet, a corresponding oil flow input or oil flow output port being formed on the base plate to be offset toward an outside of a projection configuration region of the laminated core and an oil passage is extended within the base plate to bridge over both of inside and outside of the projection configuration region of the laminated core to connect at least one of the oil flow inlet and the oil flow outlet to the corresponding oil flow input port of the base plate or oil flow output port of the base plate.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a structure of an oil cooler, forexample, mounted in an engine block of an internal combustion engineequipped in a vehicle or mounted in a transmission casing of anautomatic transmission equipped in the vehicle.

(2) Description of Related Art

A, so-called, laminated core type oil cooler in which a plurality ofcore plates are laminated in a multiple stage is a representative oilcooler of this kind. In such a laminated core type oil cooler asdescribed above, a thick plate formed (namely, thick) base plate whichfunctions as an attachment section of the laminated core plates to amating equipment (for example, the mating equipment is constituted by anengine block or a transmission casing) is installed at a lowest stage(nearest to an attachment surface of the mating equipment) of thelaminated cores which are core plate laminating bodies. In a case wherean attention has been only paid to a flow of a cooled medium such asoil, supply and reception of oil and so forth are directly carried outbetween the mating equipment through flow holes formed on the baseplate.

On the other hand, due to a restraint on a layout of the matingequipment, positions of an oil flow-in hole and an oil flow-out hole ofthe oil cooler are not always coincident with positions of the oilflow-out hole and the oil flow-in hole of the mating equipment. In sucha case as described above, an elongated hole shaped passage whichtraverses within two sheet structured base plate as described in a firstpreviously proposed oil cooler disclosed in a Japanese PatentApplication First Publication No. 2010-060168 published on Mar. 18, 2010or the similar passage is needed to be installed on a seated surface ofthe mating equipment as described in a second previously proposed oilcooler disclosed in a Japanese Patent Application First Publication No.2010-265861 published on Nov. 25, 2010 (which corresponds to an EuropeanPatent Application Publication No. EP 2 253 811). Thus, a continuity ofpassage between the oil cooler and the mating equipment is assured.

SUMMARY OF THE INVENTION

However, in the structure of oil cooler described in the firstpreviously proposed oil cooler, both of the flow-out hole and theflow-in hole at the mating equipment in addition to the flow-in hole andthe flow-out hole at the oil cooler side are assumed to be within aprojection configuration region of the laminated core in a core platelaminated direction, a desired object cannot be accomplished in a casewhere positions of the flow-out hole and flow-in hole at the matingequipment are, for example, set at an outside of the projectionconfiguration region of the laminated core due to the restraint of thelay out of the mating equipment.

In the structure of the oil cooler described in the Japanese PatentApplication First Publication No. 2010-265861, as is different from thatdescribed in the Japanese Patent Application First Publication No.2010-060168, the desired object can be accomplished even thoughpositions of the flow-out hole and the flow-in hole at the matingequipment are set at the outside of the projection configuration regionof the laminated core. However, it is necessary to perform a groovemachining or so forth which is to be a passage for the mating equipmentwhich has the restraint on the layout and a manufacturing cost isaccordingly compelled to be increased. In addition, since a region to besealed by means of a seal ring is necessarily increased along with thegroove machining to form the passage, it is necessary to simultaneouslymachine the seal ring groove to accept the seal ring. Therefore, ahigher manufacturing cost is compelled to be increased. Especially, itis not favorable that the structure of the seated surface correspondingsection of the mating equipment becomes complicated.

It is, therefore, an object of the present invention to provide astructure of an oil cooler which is capable of accomplishing the desiredobject described above especially without introductions of thecomplication of the structure of the mating equipment and of theincrease in the manufacturing cost.

According to one aspect of the present invention, there is provided withan oil cooler comprising: a laminated core including a multiple numberof plates laminated to form alternately a coolant chamber and an oilchamber between the mutually adjacent plates, the laminated corefunctioning to be a heat exchanger; a base plate on which the laminatedcore is overlapped and having a configuration larger than a projectionconfiguration region of the laminated core in a plate laminationdirection of the laminated core, the base plate functioning to be anattachment section of the laminated core to a mating equipment; oil flowinput and output ports respectively opened at an attachment surface ofthe base plate to the mating equipment and connected to oil passages ofthe mating equipment opened at a seated surface of the mating equipmentto the base plate; oil flow inlet and oil flow outlet respectivelyopened on the laminated core itself at overlapped parts of the laminatedcore and the base plate, with respect to at least one of the oil flowinlet and the oil flow outlet, the corresponding oil flow input or oilflow output port being formed on the base plate to be offset toward anoutside of the projection configuration region of the laminated core;and an oil passage extended within the base plate to bridge over both ofinside and outside of the projection configuration region of thelaminated core to connect at least one of the oil flow inlet and the oilflow outlet to the corresponding oil flow input port of the base plateor oil flow output port of the base plate.

According to another aspect of the present invention, there is providedwith an oil cooler, comprising: a heat exchanger constituted by aplurality of plates laminated to form alternately a plurality of coolantchambers and a plurality of oil chambers, each coolant chamber beingconnected to coolant input and output pipes and each oil chamber beingconnected to a corresponding one of oil passages of a mating equipmentmounted in a vehicle; a plate form attachment section configured toattach the heat exchanger onto the mating equipment, the plate formattachment section being overlapped with the heat exchanger and having aconfiguration larger than a projection configuration region of the heatexchanger in a plate form lamination direction of the heat exchanger;oil flow input and output ports respectively opened at an attachmentsurface of the plate form attachment section to the mating equipment andconnected to the oil passages of the mating equipment which are openedat a seated surface of the mating equipment; and oil flow inlet andoutlet respectively opened on the heat exchanger through which oil iscaused to flow into and out of each oil chamber of the heat exchanger, aposition of at least one of the oil flow input and output ports of theplate form attachment section being offset from the corresponding one ofthe oil flow inlet and outlet of the heat exchanger toward an externalto the projection configuration region and the plate form attachmentsection having an oil passage extended over both of internal andexternal to the projection configuration region of the heat exchanger toconnect at least one of the oil flow inlet and outlet to thecorresponding one of the oil flow and output ports of the plate formattachment section.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an oil cooler representing a first preferredembodiment according to the present invention.

FIG. 2 is a bottom view of an oil cooler shown in FIG. 1.

FIG. 3 is a cross sectional view of the oil cooler cut away along a lineA-A in FIG. 1.

FIG. 4 is an exploded perspective view of the oil cooler shown in FIG.3.

FIG. 5 is an essential part expanded view of a fin plate of the oilcooler shown in FIGS. 3 and 4.

FIG. 6 is an explanatory view representing a flow of oil at a partcorresponding to a cross section cut away along a lien A-A in FIG. 1.

FIG. 7 is an explanatory view representing a flow of a coolant at a partcorresponding to a cross section cut away along a line B-B in FIG. 1.

FIG. 8 is an essential part cross sectional view of the oil coolerrepresenting a second preferred embodiment according to the presentinvention.

FIG. 9 is an essential part cross sectional view of the oil coolerrepresenting a third preferred embodiment according to the presentinvention.

FIG. 10 is an essential part cross sectional view of the oil coolerrepresenting a fourth preferred embodiment according to the presentinvention.

FIG. 11 is an essential part cross sectional view of the oil coolerrepresenting a fifth preferred embodiment according to the presentinvention.

FIG. 12 is an essential part cross sectional view of the oil coolerrepresenting a sixth preferred embodiment according to the presentinvention.

FIG. 13 is an essential part cross sectional view of the oil coolerrepresenting a seventh preferred embodiment according to the presentinvention.

FIG. 14 is an essential part cross sectional view of the oil coolerrepresenting an eighth preferred embodiment according to the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will, hereinafter, be made to the drawings in order tofacilitate a better understanding of the present invention. FIGS. 1through 7 show a first preferred embodiment of an oil cooler accordingto the present invention. FIG. 1 shows a plan view of the oil cooler andFIG. 2 shows a bottom view of the oil cooler, respectively. In addition,FIG. 3 shows a cross sectional view of the oil cooler cut away along aline A-A in FIG. 1 as an attachment state of the oil cooler and FIG. 4shows an exploded view of the same oil cooler.

As shown in FIGS. 1, 2, and 3, oil cooler 1 is constituted by alaminated core 3 which is a lamination of core plates 5, 5, . . . , finplates 6, 6, . . . , and embossed plates 7, 7, . . . (as will bedescribed later) with a predetermined regularity and by a base plate 2of a two-layer structure disposed at a lower side of laminated core 3 soas to be overlapped on the lower side of laminated core 3. Whilelaminated core 3 functions as a heat exchanger as will be describedlater, base plate 2 functions as an attachment flange section to atransmission casing 4 of, for example, an automatic transmission as amating equipment. As appreciated from FIGS. 1 and 3, laminated core 3 isof an approximately square shape in a plan view (as viewed from a top)and, on the other hand, base plate 2 is formed to have a larger polygonshape than the projection configuration of laminated core 3.

It should be noted that all of components of oil cooler 1 are made ofaluminum and the mating equipment may be an engine block or an oil panof an internal combustion engine.

Laminated core 3 is, as shown in FIGS. 3 and 4, constituted by threecomponents of thin plate core plates 5 having holes, fin plate 6, andembossed plate 7 on which a multiple number of fine embossed sectionsare formed and having the holes as one group, these three componentsbeing laminated over n stages (n denotes a natural number and, in thecase of FIG. 3, n is four). In addition, for an uppermost stage of thegroups of the plate structure, another core plate 8 having the holes islaminated in place of embossed plate 7 and a top plate 9 is laminatedover other core plate 8. Furthermore, a coolant (cooling water) inputpipe 10 and a coolant (cooling water) output pipe 11 are, respectively,connected to top plate 9. These pipes 10, 11 are connected to a waterjacket of the engine or so forth.

In addition, each of fin plates 6 is depicted in such a thin plate shapeas a case of FIG. 4 but is, actually, formed by bending in a, so-called,corrugated fin shape as shown in FIG. 5. Junctions of mutual platesshown in FIG. 4 forming laminated core 3 and the junction of top plate 9with each pipe 10, 11 are carried out by brazing.

In such a plate structure as described above, an oil chamber 12 isformed to include fin plate 6 between core plate 5 and embossed plate 7and a coolant chamber 13 is formed between embossed plate 7 and coreplate 5, as appreciated from FIGS. 3 and 6. In other words, oil chamber12 and coolant chamber 13 are alternatively formed for each one stage inthe lamination direction of each plate in laminated core 3. Thus,laminated core 3 functions as a heat exchanger with oil as a cooledmedium and with coolant (cooling water) as a cooling medium. It shouldbe noted that FIG. 6 shows a direction of oil in laminated core 3 in thecross section cut away along line A-A in FIG. 1.

In addition, embossed sections 15, 15 are previously formed onperipheral edges of a pair of holes 14 formed on a diagonal line of eachembossed plate 7 and these embossed sections 15 are brazed to lowersurface parts of peripheral edge sections of a pair of holes 16 formedon the diagonal line of each core plate 5 located above thecorresponding one of embossed plate 7 (refer to FIG. 4). Thus, as shownin FIGS. 3 and 6, communication passages 17, 18 to communicaterespective oil chambers 12 are formed in laminated core 3 in a directionin which laminated core is cut vertically. Then, oil is directed fromone communication passage 17 toward other communication passage 18 viarespective oil chambers 12.

The structure of communication passages described above is basically thesame as that in the case of the coolant (cooling water) side. That is tosay, embossed sections 20 are previously formed on peripheral edgesections of a pair of holes 19 formed on the diagonal line of each coreplate 5 and these embossed sections 20 are brazed to lower surface partsof peripheral edge sections of a pair of holes 21 formed on the diagonalline of each core plate 5 located above the corresponding one ofembossed plate 7 (refer to FIG. 4). Thus, at a portion of laminated core3, communication passages 22, 23 to communicate respective coolantchambers 13 are formed in a direction in which laminated core 3 isvertically cut as shown in FIG. 7 and the coolant introduced fromcoolant input pipe 10 is directed from one communication passage 22 tothe other communication passage 23 via respective coolant chambers 13.

It should be noted that the structure of laminated core 3 describedabove according to the plate structure is, basically the same asdescribed in the Japanese Patent Application First Publication No.2010-060168 described in the BACKGROUND OF THE INVENTION.

Base plate 2 is, as shown in FIGS. 1. 3, and 4, constituted by a baseplate main frame 24 which is one plate element placed at an oppositeside to laminated core 3 and a distance plate 25 overlapped on baseplate main plate 24 which is the other plate element placed at the sideof laminated core 3. Both of these base plate main frame 24 and distanceplate 25 are brazed together. Laminated core 3 is similarly brazed ontodistance plate 25. Especially, as appreciated from FIG. 3, both ofthickness and shape of base plate main frame 24 are set to be largerthan those of distance plate 25. A bolt 27 is inserted into eachattachment hole 26 to fix base plate 2 to transmission casing 4 which isthe mating equipment.

An oil passage 28 which provides an oil flow output side through whichoil within oil chambers 12 is caused to flow out and an oil passage 29which provides an oil flow output side through which oil within oilchambers 12 is caused to flow in and oil passage 29 through which oilwithin transmission casing 4 is caused to flow toward oil chambers 12 isopened on seated surface 4 a of transmission casing 4 on which oilcooler 1 described above is attached. Then, flow output side oil passage28 is connected with oil flow inlet 30 located at the lowest surface oflaminated core 3 and flow input side oil passage 29 is connected withoil flow outlet 31 located at the lowest surface of laminated core 3,respectively. It should be noted that either one of the pair of holes 16formed on the lowest stage of core plates 5 corresponds to oil flowinlet 30 and the other of pair of holes 16 corresponds to oil flowoutlet 31.

As appreciated from FIG. 3, a span formed between flow output side oilpassage 28 and flow input side oil passage 29 is set to be larger thanthe span formed between oil flow inlet 30 and oil flow outlet 31 atlaminated core 3 side and flow input side oil passage 29 is set to becoincident with oil flow outlet 31 in a region of a projectionconfiguration (a projection configuration in the lamination direction ofeach plate constituting laminated core 3) of laminated core 3. On theother hand, flow output side oil passage 28 is not set within the regionof the projection configuration of laminated core 3 but is set at anoutside of the projection configuration region so as to be offsetlargely from oil flow inlet 30.

When flow output side oil passage 28 is connected to oil flow inlet 30on the lowest surface of laminated core 3 and flow input side oilpassage 29 is connected to oil flow outlet 31 on the lowest surface oflaminated core 3, respectively, in addition to the difference inmagnitude between the spans described above, a function to becompensated for an offset quantity of flow output side oil passage 28with respect to oil flow inlet 30 at laminated core 3 side is providedfor base plate 2.

More specifically, as appreciated from FIG. 3, in a state in which oilcooler 1 is fixed to a normal (or a predetermined) position oftransmission casing 4 which is the mating equipment by means of bolts27, oil flow outlet 31 at laminated core 3 side is set so that oil flowoutlet 31 at laminated core side 3 is positionally set to be coincidentwith flow input side oil passage 29 at the transmission casing 4 side.In order to connect these oil flow outlet 31 and oil flow input side oilpassage 29, oil flow output ports 32, 32 which are penetrated in platethickness directions of base plate main frame 24 and distance plate 25and which are opened on attachment surface 24 a to transmission casing 4(refer also to FIG. 4). In addition, an annular groove section 33 whichis concentric to oil flow output ports 32 and which surrounds oil outputport 32 is formed on attachment surface 24 a (also refer to FIG. 2) ofbase plate main frame 24. An O ring 34 as a seal member which is fittedand retained in annular groove section 33 serves to seal its connectionsection between base plate main frame 24 and transmission casing 4.

Since flow output side oil passage 28 at transmission casing 4 side withrespect to oil flow inlet 30 of laminated core 3 is largely offsettoward the outside of the projection configuration region of laminatedcore 3, both of oil flow inlet 30 and flow output side oil passage 28are connected together via an oil passage 35 formed between base platemain frame 24 and distance plate 25 constituting base plate 2. This oilpassage 35 is extended over both of inside and outside of the projectionconfiguration region to connect between oil flow inlet 30 at laminatedcore 3 side and flow output side oil passage 28 at transmission casing 4side.

In more details, as shown in FIGS. 3 and 4, an inner communication port36 is formed on distance plate 25 as one plate element of laminated core3 side at a position at which inner communication port 36 is coincidentwith oil flow inlet 30 at laminated core 3 side and elongated holeshaped and groove shaped inner passage section 37 which is mated oroverlapped with inner communication port 36 and which is extendedbetween both of inner and outer projection configuration region oflaminated core 3 is formed on base plate main frame 24 which is theother plate element at the opposite side of laminated core 3. This innerpassage section 37 is formed, for example, by machining through an endmill or by coining with a use of a press.

In addition, a bead-shaped embossed section 38 is protruded fromdistance plate 25 at the outside of the projection configuration regionof laminated core 3 and on an extension line of inner passage section 37at base plate main frame 24 side. Thus, this embossed section 38 isoffset with inner passage section 37 in the plate thickness direction ofbase plate 2 but is partially overlapped on and communicated with innerpassage section 37 and an elongated hole shaped outer passage section 39is extended toward an anti-projection configuration region (an oppositeside of the projection configuration region) of laminated core 3,namely, so as to be overlapped on flow output side oil passage 28 oftransmission casing 4 side.

Furthermore, an oil flow input port 40 is opened and formed which ispenetrated in the plate thickness direction of base plate main frame 24to open at attachment surface 24 a to transmission casing 4. An annulargroove section 41 which is concentric to this oil flow in port 40 isformed on attachment surface 24 a so as to surround oil flow in port 40.An O ring 42 as a seal member which is fitted and retained in annulargroove section 41 serves to seal its connection section between baseplate main frame 24 and transmission casing 4.

Hence, according to oil cooler 1 configured in the way described above,as appreciated from FIG. 3, even if the span formed between flow outputside oil passage 28 at transmission casing 4 side (which is the matingequipment) and flow input side oil passage 29 is larger than the spanformed between oil flow inlet 30 and oil flow outlet 31 at laminatedcore 3 side and flow output side oil passage 30 and flow input side oilpassage 28 is largely offset from oil flow inlet 30 of laminated core 3side at the outside of the projection configuration region of laminatedcore 3, oil passage 35 required for the supply and reception of oilbetween oil cooler 1 and mating equipment such as transmission casing 4can be secured with no forcible effort without carrying out a groovemachining on seated surface 4 a of transmission casing 4.

Especially, outer passage section 39 which is a part of oil passage 35is formed with embossed section 38 which is a protrusion of a part ofdistance plate 25 which is the one plate element and part of embossedsection 38 and the seal section constituted by O ring 42 are overlappedtogether in the plate thickness direction so that a total thickness ofbase plate 2 is partially large. However, since embossed section 38 isset on base plate 2 at the outside of the projection configurationregion of laminated core 3, a protrusion height of embossed section 38gives no influence on a total thickness of base plate 2 in theprojection configuration region of laminated core 3, namely, the totalthickness of base plate 2 just below laminated core 3. Therefore, thethickness of base plate 2 just below laminated core 3 and, in turn, aheight of whole oil cooler 1 including laminated core 3 in addition tobase plate 2 can be suppressed. The restraint on layout of the positionat which oil cooler 1 is to be installed can be relieved and the heightof whole oil cooler 1 can contribute on an improvement on easiness ofmounting of oil cooler 1 in the vehicle or so forth.

In addition, when oil cooler 1 described above is applied to the matingequipment having the different specification of span formed between flowoutput side oil passage 28 and flow input side oil passage 29, aspecification on base plate 2 to be combined with laminated core 3 maybe modified. Thus, a easier correspondence to the different span can bemade.

FIG. 8 shows a second preferred embodiment of oil cooler 1 according tothe present invention and FIG. 9 shows a third preferred embodiment ofoil cooler 1 according to the present invention. It should be noted thatthe same reference numerals are designated for the like elements shownin FIG. 3.

In the second embodiment shown in FIG. 8, base plate main frame 44constituting base plate 2 is partially supported by transmission casing4 without whole surface contact of base plate main frame 44 againsttransmission casing 4 which is the mating equipment.

For example, a case where a tightening section by means of bolts 27 inaddition to flow output side oil passage 28 and flow input side oilpassage 29 is set on a boss section 4 b projected from a general sectionof transmission casing 4 is supposed. On the above-describedsupposition, as shown in FIG. 8, an embossed section 48 is protruded onbase plate main frame 44 constituting base plate 2 together withdistance plate 25 toward a downward direction.

Consequently, an elongated hole shaped space as inner passage section 37which is a part of oil passage 35 is secured.

In a case of the third embodiment shown in FIG. 9, on an assumption ofthe same structure as FIG. 8, base plate main frame 54 is set to bethinner than that (48) in the case of FIG. 8 and an annular groovesection 51 housing O ring 42 which is the seal member is formed onseated surface 4 a of boss section 4 b.

The same advantages as those in the case of the first embodiment can beobtained in these second and third embodiments. In addition, a passagecross sectional area of inner passage section 37 can sufficiently besecured. Especially, in the third embodiment shown in FIG. 9, the totalthickness of base plate 2 can be smaller (thinner) according to the thinplating of base plate main frame 54 and the weight of base plate 2 canbe lighter although it is necessary to carry out a machining of annulargroove section 51 of transmission casing 4 side.

FIG. 10 shows a fourth preferred embodiment of the oil cooler accordingto the present invention. FIG. 11 shows a fifth preferred embodiment ofthe oil cooler according to the present invention. FIG. 12 shows a sixthpreferred embodiment of the oil cooler according to the presentinvention. The same reference numerals are designated for the likeelements common to FIG. 3.

In the fourth embodiment shown in FIG. 10, distance plate 65 is madethicker than distance plate 25 shown in FIG. 3, distance plate 65constituting base plate 2 together with base plate main frame 64. Inplace of forming inner passage section 37 on base plate main frame 64(as shown in FIG. 3), an elongated hole shape oil passage 55 is formedon distance plate 65 together with inner communication port 36 by acoining with a use of a press or by machining. This oil passage 55 hasno offset in the plate thickness direction of base plate 2 as isdifferent from FIG. 3.

In the fifth embodiment shown in FIG. 11, in place of forming innerpassage section 37 as shown in FIG. 3 on base plate main frame 64, anembossed section 58 is protruded from distance plate 75 toward flowoutput side oil passage 28 located at the outside of the projectionconfiguration region of laminated core 3. Thus, the elongated holeshaped space as oil passage 85 together with inner communication port 36is secured. This oil passage 85 has no offset in the plate thicknessdirection of base plate 2 as is different from that in the case of FIG.3.

In the sixth preferred embodiment shown in FIG. 12, in place ofprotruding embossed section 68 in the downward direction from theprojection configuration region of laminated core 3 toward flow outputside oil passage 28 which is outside of the projection configurationregion from base plate main frame 74 as is different from FIG. 3 so thatthe elongated hole shaped space is secured as oil passage 105 and onlyinner communication port 36 is formed on distance plate 95. This oilpassage 105 has no offset in the plate thickness direction of base plate2 as is different from that shown in FIG. 3.

The similar advantages as those in the case of the first embodimentrepresentatively shown in FIG. 3 can be obtained in the case of thefourth, fifth, and sixth embodiments.

FIG. 13 shows a seventh preferred embodiment of oil cooler according tothe present invention and FIG. 14 shows an eighth preferred embodimentaccording to the present invention. The same reference numerals aredesignated for the like elements common to FIG. 3.

In the seventh embodiment shown in FIG. 13, in place of forming outerpassage section 39 by the use of embossed section 38 as shown in FIG. 3,an elongated hole shaped outer passage section 49 is formed on distanceplate 115 to be penetrated in the plate thickness direction of distanceplate 115 and is partially sealed with another cover plate 125. Itshould be noted that cover plate 125 constituting base plate 2 is joinedon distance plate 115 by means of, for example, brazing.

According to the seventh embodiment shown in FIG. 13, base plate 2 ispartially of the, so-called, three-ply structure. However, as comparedwith base plate 2 formed through the embossing, it is easy in securingouter passage section 49. Since thin plate cover plate 125 is used, thetotal thickness of base plate 2 at least at a part of base platecorresponding to outer passage section 49 can advantageously be madesmall.

In the eighth embodiment shown in FIG. 14, base plate 2 itself hassubstantially the three-ply structure by the use of both of a firstdistance plate 135 and a second distance plate 145 in addition to baseplate main frame 64 as one of the plate elements of base plate 2. Then,an elongated hole shaped oil passage 155 is formed which is penetratedfrom first distance plate 135 toward flow output side oil passage 28located at the outside of the projection configuration region oflaminated core 3. On the other hand, inner communication port 36 isformed on second distance plate 145. Elongated hole shaped oil passage155 at second distance plate 135 side is sealed by second distance plate145. This oil passage 155 has no offset in the plate thickness directionof base plate 2 as is different from FIG. 3.

According to the eighth preferred embodiment, although the number ofplates as the plate elements constituting base plate 2 is three, thepressing for the respective plate elements can advantageously befacilitated.

It should, herein, be noted that, in each embodiment described above,oil flow inlet 30 and flow output side oil passage 28 at transmissioncasing 4 side which is offset from oil flow inlet 30 are interconnectedvia oil passage 35. However, the present invention is, of course,applicable to a case where oil flow outlet 31 and flow input side oilpassage 29 are offset.

In addition, depending upon the specification of oil cooler 1 or therelationship with the mating equipment, as the oil flow within the oilcooler, the flow of oil introduced from oil flow inlet 30 via oil flowinput port 40 and inner passage section 37 shown in FIG. 3 is foldedback toward an inside of top plate 9 and is caused to flow out to themating equipment utilizing effectively hole section H penetrated at thecenter section of laminated core 3 shown in FIGS. 1 and 3. In this case,oil flow out port 32 is needed to be formed at a position coincidentwith hole section H. It is of course that the present invention isapplicable to the oil cooler described above.

Technical concepts derived from the present invention will be describedin details below. That is to say, an oil cooler comprises: a laminatedcore including a multiple number of plates laminated to form alternatelya coolant chamber and an oil chamber between the mutually adjacentplates, the laminated core functioning to be a heat exchanger; a baseplate on which the laminated core is overlapped and having aconfiguration larger than a projection configuration region of thelaminated core in a plate lamination direction of the laminated core,the base plate functioning to be an attachment section of the laminatedcore to a mating equipment; oil flow input and output ports respectivelyopened at an attachment surface of the base plate to the matingequipment and connected to oil passages of the mating equipment openedat a seated surface of the mating equipment to the base plate; oil flowinlet and oil flow outlet respectively opened on the laminated coreitself at overlapped parts of the laminated core and the base plate,with respect to at least one of the oil flow inlet and the oil flowoutlet, the corresponding oil flow input or oil flow output port beingformed on the base plate to be offset toward an outside of theprojection configuration region of the laminated core; and an oilpassage extended within the base plate to bridge over both of inside andoutside of the projection configuration region of the laminated core toconnect at least one of the oil flow inlet and the oil flow outlet tothe corresponding oil flow input port of the base plate or oil flowoutput port of the base plate.

It should, herein, be noted that the base plate may be formed of asingle sheet of plate element or may be formed of plural sheets of plateelements.

In the latter case, in order to reduce the total thickness size(dimension) of the base plate at least in the projection configurationregion of the laminated core as small as possible, as described in theclaim 1, it is desirable that the base plate is formed with at least twosheets of mutually overlapped plate elements and the oil passage of thebase plate is formed between the two sheets of plate elements.

More desirably, as described in the claim 3, the oil passage of the baseplate includes: an inner passage section located near to the projectionconfiguration region of the laminated core; and an outer passage sectionlocated nearer to an opposite side of the projection configurationregion of the laminated core than the inner passage section and locatednear to the laminated core with respect to a plate thickness directionof the base plate, both of the inner and outer passage sections beingcommunicated with each other and being offset from each other in theplate thickness direction of the base plate.

Specifically, as described in the claim 4, the outer passage section isformed on one of the two sheets of the plate elements at the laminatedcore side and the inner passage section is formed on the other of thetwo sheets of plate elements at the opposite side of the laminated core,respectively.

More specifically, as described in the claim 5, an inner communicationport connecting either the oil flow inlet or the oil flow outlet to theinner passage section and the outer passage section are formed on one ofthe plate elements located at the laminated core side and the oil flowinput port connecting one of the oil passages of the mating equipment tothe outer passage section and the inner passage section are formed onthe other of the plate elements located at an opposite side of thelaminated core.

Hence, as the invention described in at least one claim 1, the oilpassage extended over both of the inside and outside of the projectionconfiguration of the laminated core is formed in the base plate. Thus,due to the restraint of the layout of the mating equipment, with respectto the position of the oil flow input port of the oil cooler side or theoil flow output port of the oil cooler side is not coincident with theposition of the corresponding oil passage of the mating equipment to theoil flow input port or the oil flow output port so that, even if theposition of the oil passage of the mating equipment is set toward theoutside of the projection configuration region of the laminated core, itis possible to accomplish the desired object. Therefore, it becomesunnecessary to form the groove section (as is described in the secondpreviously proposed oil cooler described in the BACKGROUND OF THEINVENTION) on the seated surface of the mating equipment.

This application is based on a prior Japanese Patent Application No.2011-026753 filed in Japan on Feb. 10, 2011. The entire contents of thisJapanese Patent Application No. 2011-026753 are hereby incorporated byreference. Although the invention has been described above by referenceto certain embodiments of the invention, the invention is not limited tothe embodiment described above. Modifications and variations of theembodiments described above will occur to those skilled in the art inlight of the above teachings. The scope of the invention is defined withreference to the following claims.

1. An oil cooler comprising: a laminated core including a multiplenumber of plates laminated to form alternately a coolant chamber and anoil chamber between the mutually adjacent plates, the laminated corefunctioning to be a heat exchanger; a base plate on which the laminatedcore is overlapped and having a configuration larger than a projectionconfiguration region of the laminated core in a plate laminationdirection of the laminated core, the base plate functioning to be anattachment section of the laminated core to a mating equipment; oil flowinput and output ports respectively opened at an attachment surface ofthe base plate to the mating equipment and connected to oil passages ofthe mating equipment opened at a seated surface of the mating equipmentto the base plate; oil flow inlet and oil flow outlet respectivelyopened on the laminated core itself at overlapped parts of the laminatedcore and the base plate, with respect to at least one of the oil flowinlet and the oil flow outlet, the corresponding oil flow input or oilflow output port being formed on the base plate to be offset toward anoutside of the projection configuration region of the laminated core;and an oil passage extended within the base plate to bridge over both ofinside and outside of the projection configuration region of thelaminated core to connect at least one of the oil flow inlet and the oilflow outlet to the corresponding oil flow input port of the base plateor oil flow output port of the base plate.
 2. The oil cooler as claimedin claim 1, wherein the base plate is formed with at least two sheets ofmutually overlapped plate elements and the oil passage of the base plateis formed between the two sheets of plate elements.
 3. The oil cooler asclaimed in claim 2, wherein the oil passage of the base plate includes:an inner passage section located near to the projection configurationregion of the laminated core; and an outer passage section locatednearer to an opposite side of the projection configuration region of thelaminated core than the inner passage section and located near to thelaminated core with respect to a plate thickness direction of the baseplate, both of the inner and outer passage sections being communicatedwith each other and being offset from each other in the plate thicknessdirection of the base plate.
 4. The oil cooler as claimed in claim 3,wherein the outer passage section is formed on one of the two sheets ofthe plate elements at the laminated core side and the inner passagesection is formed on the other of the two sheets of plate elements atthe opposite side of the laminated core, respectively.
 5. The oil cooleras claimed in claim 4, wherein an inner communication port connectingeither the oil flow inlet or the oil flow outlet to the inner passagesection and the outer passage section are formed on one of the plateelements located at the laminated core side and the oil flow input portconnecting one of the oil passages of the mating equipment to the outerpassage section and the inner passage section are formed on the other ofthe plate elements located at an opposite side of the laminated core. 6.The oil cooler as claimed in claim 1, wherein the mating equipment is atransmission casing of an automatic transmission mounted in a vehicle.7. The oil cooler as claimed in claim 6, wherein the oil flow input portof the base plate is offset with respect to the corresponding oil flowinlet) of the laminated core toward the outside of the projectionconfiguration region of the laminated core.
 8. The oil cooler as claimedin claim 7, wherein a base plate main frame constituting the base plateand located at the opposite side of the laminated core is partiallysupported by the transmission casing.
 9. The oil cooler as claimed inclaim 8, wherein the base plate main frame is embossed and protrudedtoward an inside of the transmission casing and joined with a bosssection of the transmission casing.
 10. The oil cooler as claimed inclaim 7, wherein an inner communication port connecting the oil flowinlet to the oil passage of the base plate is integrally formed with theoil passage of the base plate connected directly between the innercommunication port and the oil flow inlet port without an offset of theoil passage of the base plate in a plate thickness direction of the baseplate.
 11. The oil cooler as claimed in claim 10, wherein the base platecomprises: an embossed section protruded from the projectionconfiguration region of the laminated core toward one of the oilpassages of the transmission casing through which oil is caused to flowtoward the oil flow input port; and a base plate main frame on which theoil flow input port is formed.
 12. The oil cooler as claimed in claim10, wherein the base plate comprises: an embossed section formed on abase plate main frame of the base plate and protruded from theprojection configuration region of the laminated core toward one of theoil passages through which oil is caused to flow toward the oil flowinput port and a distance plate on which only the inner communicationport is formed.
 13. The oil cooler as claimed in claim 7, wherein theoil passage of the base plate comprises: an inner passage sectionlocated near to the projection configuration region of the laminatedcore; an outer passage section located nearer to an opposite side of theprojection configuration region of the laminated core than the innerpassage section and located near to the laminated core with respect to aplate thickness direction of the base plate, both of the inner and outerpassage sections being communicated with each other and being offsetfrom each other in the plate thickness direction of the base plate andan inner communication port connecting the oil flow inlet to the innerpassage section is formed on the base plate.
 14. The oil cooler asclaimed in claim 13, wherein the base plate comprises a cover plate, adistance plate on which the inner communication port is formed, and abase plate main frame located at the seated surface of the transmissioncasing, the outer passage section being formed between the cover plateand the outer passage and the inner passage section being formed betweenthe distance plate and the base plate main frame.
 15. The oil cooler asclaimed in claim 10, wherein the base plate comprises a base plate mainframe located at the seated surface of the transmission casing, a firstdistance plate, and a second distance plate located at the laminatedcore side, the inner communication port being formed on the seconddistance plate and the oil passage of the base plate being defined bythe first distance plate, the second distance plate, and the base platemain frame.
 16. An oil cooler, comprising: a heat exchanger constitutedby a plurality of plates laminated to form alternately a plurality ofcoolant chambers and a plurality of oil chambers, each coolant chamberbeing connected to coolant input and output pipes and each oil chamberbeing connected to a corresponding one of oil passages of a matingequipment mounted in a vehicle; a plate form attachment sectionconfigured to attach the heat exchanger onto the mating equipment, theplate form attachment section being overlapped with the heat exchangerand having a configuration larger than a projection configuration regionof the heat exchanger in a plate form lamination direction of the heat,exchanger; oil flow input and output ports respectively opened at anattachment surface of the plate form attachment section to the matingequipment and connected to the oil passages of the mating equipmentwhich are opened at a seated surface of the mating equipment; and oilflow inlet and outlet respectively opened on the heat exchanger throughwhich oil is caused to flow into and out of each oil chamber of the heatexchanger, a position of at least one of the oil flow input and outputports of the plate form attachment section being offset from thecorresponding one of the oil flow inlet and outlet of the heat exchangertoward an external to the projection configuration region and the plateform attachment section having an oil passage extended over both ofinternal and external to the projection configuration region of the heatexchanger to connect at least one of the oil flow inlet and outlet tothe corresponding one of the oil flow and output ports of the plate formattachment section.